1. Field of the Invention
The present invention relates to a device for measuring and/or displaying various data representation of heart motion such as sphygmogram data, sphygmus data, highest and lowest blood pressure data, blood flow rate data, electrocardiographic wave data and the like.
2. Description of Related Art
Devices for measuring and displaying sphygmus and highest and lowest blood pressure are available in the market and are used for keeping health. Among such known devices are involved pulsimeters for measuring sphygmus which, with use of LED and transistor arrangements, detect changes of hemoglobin in blood caused by pulsatory motion and senses electrocardiographic R-waves accompanied by heart motion, and haemadynamometers which, with use of an air pump, pressure tube and an acoustic or optical sensor, sense blood pressure by installing a cuff on a fingertip or arm of a subject.
Such devices, however, have drawbacks that are inconvenient in handling, requiring much time for a measurement, and are so large in size that it can not be carried in hand.
Under the circumstances, a device has been proposed which obtains blood pressure data without using an air pump. For example, U.S. Pat. No. 4,869,262 discloses a device which comprises a pulsimeter for sensing sphygmus in a fingertip of a subject and an R-wave detector for sensing electrocardiographic R-waves in the fingertip, and which performs a certain operation on data obtained by the pulsimeter and the R-wave detector to calculate blood pressure data.
Since the above device, however, senses sphygmus and electrocardiographic R-waves each in the fingertip, it has drawbacks that precise measurements of sphygmus and electrocardiographic R-waves can not be made in case that the finger is not set to a right position. Further, the measurements are easily influenced by external noises because the device senses very weak signals. Therefore, the resultant blood pressure is not always accurate one. As described above, as the device senses very weak signals, it includes an amplifier for amplifying the sensed weak signals. It is hard to set the gain of such amplifier for properly amplifying the sensed signals, because the sensed signals vary in level from subject to subject.
Conventional pulsimeter and haemadynamometer simply display sphygmus data and blood pressure data, respectively but they do not provide appropriate data for keeping or promoting health. Therefore, these meters are not used effectively by the subject for that purpose. To keep and promote health, the subject needs other data in addition to sphygmus data and blood pressure data, which teach what kind or how much of food he should take, and/or what exercises are suitable for him to keep health or to promote health.